The invention relates to a transportable apparatus for heating food, which includes a container for receiving the food and a heating space adjoining the container, which is thermally coupled to the container by means of a common thermally-conductive wall and at the same time is separate from it and which contains a substance or a mixture of substances, which, when a liquid, particularly water, is supplied produces heat in an exothermic chemical reaction. The invention further relates to a transportable heating device, which is usable, for instance, in the aforementioned transportable apparatus for heating food.
A mixture of substances, which includes calcium oxide (CaO) and aluminum powder (Al) is disclosed, for instance, in Patent Specification EP 1126004 B1. When water is supplied, a multi-stage chemical reaction occurs, in which, on the one hand, the calcium oxide is converted with the water into calcium hydroxide with the generation of heat and in which the calcium hydroxide then reacts with the aluminum to form calcium aluminate and hydrogen, whereby further heat is produced. Temperatures of 90° C. and more may be achieved with such a mixture of substances, though it should be noted that at temperatures above 100° C. steam is additionally produced from a proportion of the water. If the reaction takes place in a closed container, the high gas pressure at temperatures above 100° C. can result in bursting of the container. Only heating to below 100° C. is therefore performed with the heating mixture proposed in the publication.
A further mixture of substances for producing heat is disclosed in DE 102008015677 A1 or in DE 202010015079 U1.
DE 202010015079 U1 discloses a container with a first receiving space for a consumable product, which is surrounded by a second receiving space, which contains a sorbent material, e.g. zeolite. The second receiving space is surrounded by a third receiving space, in which a liquid, e.g. water, is situated. The wall between the third and second receiving spaces may be ruptured such that the liquid can enter from the third receiving space into the second receiving space. The sorbent absorbs water, whereby heat is produced, which heats the product in the first receiving space. The mixing of the water, which enters the second chamber only at a few points, with the sorbent during the onset of the sorption reaction is problematic with this structural design.
In DE 102008015677 A1 a zeolite granulate and a water-containing bag are located in a closed bag. In order to produce the heat, the water bag is firstly induced to burst, whereafter the water distributes itself within the surrounding bag and acts on the zeolite granulate. The zeolite absorbs the water, whereby heat is produced. It is of disadvantage with the arrangement proposed therein that firstly a speedy distribution of the water within the bag must be achieved, which is supposed to be achieved, for instance, by water-conducting additional layers of an absorbent material. Specifically, if the water is not distributed instantaneously in the bag, it reacts initially only with the adjacent particles of the zeolite granulate, whereby this mixture then forms a barrier, which impedes further distribution of the water. The heat production is thus in turn reduced.
It is therefore the object of the invention to provide a transportable apparatus for heating food or a transportable heating device, in which the disadvantages of the prior art referred to above are avoided and high temperatures above 100° C. can be achieved, without hot vapors or unpleasant odors leaving the heating space.
This object is solved in accordance with the invention by a transportable apparatus with the features of claim 1. This object is further solved by a transportable heating device with the features of claim 20.